General Information

Serial #

N/A

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

WOOD (PEARWOOD)/ BRASS PIVOT

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

25.8 cm

Width

12.5 cm

Height

1.2 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Marine Transportation

Category

Navigation instruments & equipment

Sub-Category

N/A

Manufacturer

AKA

Unknown

Country

England

State/Province

Unknown

City

Unknown

Context

Country

Unknown

State/Province

Unknown

Period

GENERAL: 17TH & EARLY 18TH CENTURIES

Canada

Unknown

Function

INSTRUMENT USED BY MARINERS TO DETERMINE LOCAL TIME AT NIGHT, TO ESTABLISH THE TIMING OF THE FLOOD TIDE, & TO MEASURE LATITUDE. NOCTURNAL FUNCTIONED BY VIEWING POLARIS THROUGH CENTRAL SIGHT & THEN ALIGNING INSTRUMENT'S INDEX ARM WITH EITHER URSA MAJOR OR URSA MINOR.

Technical

THENOCTURNAL IS A FUNDAMENTAL PIECE IN THE HISTORY OF MARINE NAVIGATION TECHNOLOGY. IT WAS A DESCENDANT OF THE PLANISPHERIC ASTROLABE& A PRECURSOR TO THE DAVIS QUADRANT & HADLEY OCTANT, BOTH OF WHICH WERE REFINEMENTS OF THE TECHNIQUES REFLECTED IN THE NOCTURNAL. NOCTURNALS WERE WIDELY USEDBY MARINERS IN THE 17TH & EARLY 18TH CENTURIES & WERE SECOND IN IMPORTANCE ONLY TO THE COMPASS AS INSTRUMENTS OF NAVIGATION (2).

Area Notes

Unknown

Details

Markings

INCISED BLACK SCALES, NUMERALS, & LETTERING READING 'BOTH BEARS' & FOR MONTHS OF THE YEAR

Missing

N/A

Finish

NATURAL WOOD FINISH/ BRASS COLOURED METAL

Decoration

INCISED BLACK PARALLEL LINES